摘要:

AbstractThe preparation of some alkyl ethers of ortho and para hydroxybenzyl alcohol is described.

ISSN:0165-0513    

DOI:10.1002/recl.19550741202

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractThis paper describes the Raman spectroscopical investigations which contributed to the elucidation of the chemical structure of the compounds obtained by the condensation of chloral with 1,2‐dichloroethene. As has been pointed out in the chemical part of this study, decomposition (by the action of aluminium chloride) of 1,1,1,3,4,4‐hexachloro‐2‐methoxybutane yielded the same compounds, but in other proportions.The Raman spectra are discussed of various fractions, obtained through distillationin vacuo. In several of these spectra “extra lines” indicated the presence of contaminations; these have been identified by their characteristic Raman lines.“Group frequency analysis”, in addition to the chemical evidence obtained, allowed of a final conclusion concerning the structural formulae of some o

ISSN:0165-0513    

DOI:10.1002/recl.19550741203

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractDuring an investigation on compounds related to cortisone the dehydration of various 17α‐hydroxy‐20‐ketopregnanes was studied.In a recent paperBernstein et al.1) reported on the elimination of 17α‐hydroxy groups adjacent to a 20‐ketal group. These hydroxy groups were known to be stable towards phosphorus oxychloride‐pyridine at room temperature2), but with thionyl chloride‐pyridine the desired Δ16‐steroids were formed. This publication covers part of the work carried on for some time in this laboratory and prompts us to give our

ISSN:0165-0513    

DOI:10.1002/recl.19550741204

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractA calorimeter similar to the one used in the heat‐of‐mixing experiments has served for the determination of the excess molar heat capacities of the system benzene‐1,2‐dichloroethane at 7.73° C, 20.46° C, and 35.66° C. At 7.73° C and 20.46° C the agreement between the directly measured excess molar heat capacities and those derived from the heat‐of‐mixing experiments is excellent. At 35.66° C the agreem

ISSN:0165-0513    

DOI:10.1002/recl.19550741205

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractThe infrared spectrum of liquid CSCl4has been measured from 3‐25μ. The experimental results are discussed and a complete analysis of the spectrum is given.Although some corrections in his vibrational assignment had to be made, the spectrum supports the structure proposed byDuchesne1), i.e. CCl4with a chlorine atom replaced by sulphur and a chlorine atom attached to the sulphur at an angle to the CS bond.One of the fundamental frequencies shows Fermi‐splitting with a combination frequency. The difference between vapour and liquid state spectrum is used to prove the interpretation given. For comparison the shape of the Fermi‐doublet observed in the infrared spectrum of carbon tetrachloride is studied in the vapour and the liqu

ISSN:0165-0513    

DOI:10.1002/recl.19550741206

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractThe excess molar volumes on mixing benzene and 1,2‐dichloroethane have been measured at 20.00°C, 30.10°C, and 50.00°C. It appears that the excess molar volumes are of the order of 0.25 ml/mole at equimolar concentrations. A small temperature dependency has been observed.Finally some conclusions concerning this sytem have been d

ISSN:0165-0513    

DOI:10.1002/recl.19550741207

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractThe potentials of MnO2, prepared by electro‐deposition on a platinum base and containing some lower oxide, vary with the pH of the solution. In acid solutions (pH 1‐5), ΔE/ΔpHamounts to 0.120 with an Eo′ = 1.38 volts at 25° C. From pH 7‐12, ΔE/ΔpHamounts to 0.060 with an Eo′ = 1.125 volts. In acid solutions the electrodes behave like MnO2/Mn+2, and in alkaline solutions like Mn(OH)3/Mn(OH)2systems. The kinetics of the reaction in alkaline medium are discussed, and an equation expressing the variation of potential with tim

ISSN:0165-0513    

DOI:10.1002/recl.19550741208

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractA description is given of a quantitative polarographic method for determining the glycyrrhizic acid content ofsuccus liquiritiae.The succus is dissolved in dioxane‐water and after hydrolysis with dilute add the hydrolysate is extracted with chloroform. An aliquot of this extract is evaporated to dryness and the residue is taken up in alcohol. Prom this solution a polarographic test solution is prepare

ISSN:0165-0513    

DOI:10.1002/recl.19550741209

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractOn the basis of the results reported in the foregoing papers IV and V and the data obtained byBergman2) from the reduction of various aromatic hydrocarbons in ethylene glycol mono‐methyl ether Maccoll's relationship between the experimental halfwave potential and the root a of the m.o. secular equation corresponding to the lowest non‐occupied π‐electronic level has been investigated in more detail. It is shown that the half‐wave potentials of 38 alternant and non‐alternant hydrocarbons being reduced according to the mechanism inferred in paper IV satisfy the relationship:\documentclass{article}\pagestyle{empty}\begin{document}$$ \varepsilon _{1/2} = {\rm a}.\gamma - 0.85\,{\rm Volt} $$\end{document}The mean value of the resonance parameter γ in e.v. for various experimental:The half‐wave potentials of the univalent anions of various conjugated hydrocarbons determined by the equilibrium R′ + e ⇋ R″ in 96% dioxan‐water and the half‐wave potential of the radical triphenylmethyl fit the relationship.\documentclass{article}\pagestyle{empty}\begin{document}$$ \varepsilon _{1/2} = {\rm a}.\gamma - 1.05\,{\rm Volt} $$\end{document}In this case the mean value of γ following fromHückel's and Wheland'm.o. approximation becomes −2.82 ± 0.13 and −2.57 ± 0.11 e.V., respectivelly.In accordance with the discussion given in paper V the half‐wave potentials of various l‐n‐diarylpolyenes show a slight departure from the linear relationship.The addition of an electron to non‐planar hydrocarbons may involve a decrease in the mutual hindrance between the integral parts of the system, since the lenght of the carbons bonds in the negative ions formed, will be greater than in the original hydrocarbons. Owing to this “resonance stabilisation” the difference between the experimental half‐wave potential and the one computed with the aid of the linear relationship assuming a planar structure, is sometimes appreciably larger (dibiphenylene‐ethene) or smaller (cis1,2‐diphenylethene andcis, cis1,4‐diphenylbutadiene‐1,3) than we might expec

ISSN:0165-0513    

DOI:10.1002/recl.19550741210

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY

摘要:

AbstractThe conversion of some new Δ5‐steroids1) into the corresponding provitamins D is described. The preparation of a provitamin D with a side‐chain ending in a tertiary amine function has been realized by reduction of the add amide with LiAlH4.The irradiated products show only very slight anti‐rachitic prop

ISSN:0165-0513    

DOI:10.1002/recl.19550741211

出版商:WILEY‐VCH Verlag    

年代:1955

数据来源: WILEY